From 6668ed271eaefaa63e686bdfbedaeb7b8e492722 Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Fri, 4 Sep 2026 10:43:19 +0200 Subject: selftests/bpf: Reject graph kptr use after RCU unlock Add a sleepable verifier test that loads a graph-node local kptr in an explicit RCU read-side critical section, then passes its node to bpf_rbtree_remove() after the section ends. Before the verifier fix, the stale NON_OWN_REF flag makes the node look like a live borrowed reference and the program is accepted. After the fix, the pointer is demoted without NON_OWN_REF and the graph kfunc argument is rejected. Also exercise a graph kptr loaded while a spin lock provides implicit RCU protection. The pointer must be invalidated when the lock is released, which guards the required ordering between non-owning-reference invalidation and RCU demotion. Update the existing fault-protected load test state description. The post-unlock pointer no longer carries NON_OWN_REF, but remains readable because the load is rewritten to use BPF_PROBE_MEM. Signed-off-by: Kumar Kartikeya Dwivedi Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com Signed-off-by: Alexei Starovoitov --- drivers/iommu/intel/perf.h | 71 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 71 insertions(+) create mode 100644 drivers/iommu/intel/perf.h (limited to 'drivers/iommu/intel/perf.h') diff --git a/drivers/iommu/intel/perf.h b/drivers/iommu/intel/perf.h new file mode 100644 index 000000000..1d4baad7e --- /dev/null +++ b/drivers/iommu/intel/perf.h @@ -0,0 +1,71 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * perf.h - performance monitor header + * + * Copyright (C) 2021 Intel Corporation + * + * Author: Lu Baolu + */ + +enum latency_type { + DMAR_LATENCY_INV_IOTLB = 0, + DMAR_LATENCY_INV_DEVTLB, + DMAR_LATENCY_INV_IEC, + DMAR_LATENCY_NUM +}; + +enum latency_count { + COUNTS_10e2 = 0, /* < 0.1us */ + COUNTS_10e3, /* 0.1us ~ 1us */ + COUNTS_10e4, /* 1us ~ 10us */ + COUNTS_10e5, /* 10us ~ 100us */ + COUNTS_10e6, /* 100us ~ 1ms */ + COUNTS_10e7, /* 1ms ~ 10ms */ + COUNTS_10e8_plus, /* 10ms and plus*/ + COUNTS_MIN, + COUNTS_MAX, + COUNTS_SUM, + COUNTS_NUM +}; + +struct latency_statistic { + bool enabled; + u64 counter[COUNTS_NUM]; + u64 samples; +}; + +#ifdef CONFIG_DMAR_PERF +int dmar_latency_enable(struct intel_iommu *iommu, enum latency_type type); +void dmar_latency_disable(struct intel_iommu *iommu, enum latency_type type); +bool dmar_latency_enabled(struct intel_iommu *iommu, enum latency_type type); +void dmar_latency_update(struct intel_iommu *iommu, enum latency_type type, + u64 latency); +void dmar_latency_snapshot(struct intel_iommu *iommu, char *str, size_t size); +#else +static inline int +dmar_latency_enable(struct intel_iommu *iommu, enum latency_type type) +{ + return -EINVAL; +} + +static inline void +dmar_latency_disable(struct intel_iommu *iommu, enum latency_type type) +{ +} + +static inline bool +dmar_latency_enabled(struct intel_iommu *iommu, enum latency_type type) +{ + return false; +} + +static inline void +dmar_latency_update(struct intel_iommu *iommu, enum latency_type type, u64 latency) +{ +} + +static inline void +dmar_latency_snapshot(struct intel_iommu *iommu, char *str, size_t size) +{ +} +#endif /* CONFIG_DMAR_PERF */ -- cgit v1.3.1